The present invention relates generally to the field of cold storage systems, and more particularly to increasing density of Massive Array of Idle Disk (MAID) systems.
Cold storage systems often utilize MAID systems with multiple (e.g., hundreds to thousands) hard drives, most of which are powered down at any given time, to provide nearline storage of data. In some examples, MAID systems are used in “write once, read occasionally” applications, where increased storage density and decreased cost are traded for increased retrieval latency and decreased redundancy. Often, MAID systems are used to store cold data that is infrequently accessed. In some cases, cold data is kept for regulatory or historical reasons. In MAID applications, the increased latency, caused by waiting for an idle drive to power up, is traded for the increased density and lower power consumption of keeping most drives in an idle (i.e., unpowered) state. For example, when a hard drive is not actively being accessed, the storage device can be shut down. Once a drive is shut down it is not consuming power or generating heat, allowing the drive to begin to cool down.